SPECIFICATION FOR AIR DISTRIBUTION EQUIPMENT - Actionair

Noise levels generated by grilles and balancing
damper shall not exceed the levels indicated in CIBSE
Guide A or relevant CEN documentation, unless
otherwise specified.
1.1.5.2.2 Schedules: All schedules shall indicate
clearly the product specification, manufacturers name,
catalogue reference, size, volume flow rate, throw
(minimum/maximum) and pressure drop. In
addition the following should be specified: material,
finish, noise level in the occupied zone in NC or dBA,
supply and room temperature.
The following is a sample schedule:
Manufacturer:
Catalogue
Ref
Size
mm
1.1.5.3 Fixings
Volume
Flow
m 3 /s
Throw
Min/
max m
Supply air
temperature
Differential ºC
Pressure
drop Pa
Noise
NC or
dBA
Grilles shall be fixed by 1 of 4 methods:
a) screw fixing through the grille border.
b) concealed fixing by means of fastener accessible
through grille face.
c) spring fixing by means of clips attached to the grille
core or grille frame.
d) sub-frame/quick release fasteners.
Further details are given in the HEVAC Guide To Air
Distribution Technology for the Internal
Environment, and the manufacturers literature.
NOTE: Where specified grilles shall be supplied with
sub frames
1.1.5.4 Installation
Grilles and balancing dampers shall be installed in
accordance with current good practice as detailed in
the HEVAC Guide To Air Distribution Technology
for the Internal Environment.
1.2 DIFFUSERS
Generally, diffusers are mounted in the ceiling area
providing supply air. Architecturally, ceiling diffusers
can be used for the purpose of extracting air. On
occasions, radial discharge devices installed in the
floor are also referred to as diffusers.
1.2.1 Linear (Slot)Diffusers
These are air terminal devices with single or multiple
slots, each of which has an aspect ratio of greater than
10:1. Each slot may consist of a number of separate
elements. Each slot may or may not have an
adjustable control element or elements to vary the
direction or directions of the air or the air flow rate
delivered to the treated space.
When control elements are present the air discharge
pattern may be set to one ,or any combination of the
following:
Horizontal 1 way
Horizontal 2 way
Horizontal alternating discharge
Angled alternating discharge
Vertical
Fixed blade diffusers shall provide one way or two
way horizontal air diffusion patterns
1.2.2 Circular Diffusers
Adjustable circular diffusers shall be pan or multicone
type capable of being set to produce radial
horizontal or vertical air diffusion patterns.
Fixed circular diffusers shall be pan or multi-cone
type capable of producing a radial horizontal air
diffusion pattern.
1.2.3 Square and Rectangular Diffusers
Adjustable square and rectangular diffusers shall be
pan, perforated face or multi-blade type capable of
being set to produce horizontal or vertical air
diffusion patterns.
Fixed square and rectangular diffusers shall be pan,
perforated face or multi-blade type capable of
producing one, two, three or four way horizontal air
diffusion patterns as specified.
1.2.4 Swirl Diffusers
The construction of this type of diffuser causes a
swirling or higher turbulence discharge which
accelerates the mixing of the supply air into the
surrounding space. This is generally greater than the
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